Question

jon rented a car from a company that charged a daily rental fee and a mileage charge. He rented the car for 9 days and drove 300 miles and was charged $315. His friend Amanda later rented the same car for 5 days and drive 240 miles and was charged $186. What was the daily rental charge? How much did the company charge per mile?

Answer 1

let the daily rental fee be f
let the mileage charge be m

Jon: 9f + 300m = 315
3f + 100m = 105

Amanda: 5f + 240m = 186

jon x 5 -------> 15f + 500m = 525
Amanda x 3 ---> 15f + 720m = 558
subtract them:
220m = 33
m = 33/220 = 3/20 or .15
back into Jon
3f + 100(.15) = 105
f = 30

They charged $30 per day, plus 15 cents per mile